It usually takes me about 10 to 15 seconds to logon to Verichat on my BlackBerry. If it takes more than one or two minutes, then something is wrong.
I would suggest testing Reqwireless WebViewer from http://www.reqwireless.com
... It's a useful color HTML browser for your BlackBerry too.
You should call Nextel and make sure that the full Packetstream service is completely enabled on your Nextel, with static IP address enabled.
Things should be just fine in a couple of days from now, I hope -- just keep working at it, but just test briefly once a day. Call up Nextel too as well. Then everything should work after a while, if history is of any note (About 2-3 days after activation)